We took the WED concept one step further and introduced ICED – the Inter-Catalogue Energy Distance – to quantify the difference between samples of planetary systems. We demonstrated how ICED may be used as a summary statistic to compare between catalogues or samples of planetary systems.
An easy to estimate distance function between architectures of planetary systems can complement forward modeling as a tool to compare between observed and simulated samples of planetary systems. Previous works [1]}, [2]} used some linear combinations of statistical distances between the separate distributions of the planetary parameters (KS test, AD statistics, Cressie–Read statistics or a simple Euclidean distance). Much like WED, ICED suggests an integrative approach that can be useful also in comparing observed catalogues with planetary population-synthesis models of planet formation and evolution [3]}, [4]}, [5]}, comparing sub-populations from the same model as was recently used by [6]} and comparing populations produced by varying the details of a model [7]}.
